摘要
以火棘种子为试验材料,研究了萌发过程中种子吸水规律及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)活性的动态变化规律。结果表明:火棘种子吸水率随浸种时间的变化趋势近似呈"S"型曲线,最高吸水率为18.14%;其萌发过程经历快速吸水期、稳定吸水期和饱和吸水期三个阶段;不同干旱胁迫对火棘种子的萌发及萌发进程具有显著的延缓和抑制作用,且随干旱胁迫程度的加剧,萌发率显著降低,平均萌发时间逐渐加长,萌发开始时间逐渐推迟。四种抗氧化酶活性随种子萌发进程均呈多项式变化,表现为"升高-降低-升高"的趋势;在非干旱胁迫下,SOD和POD活性均在芽期达到最大值,CAT和GR均以吸胀期的活性最高,但吸胀期与芽期的CAT活性无显著差异;在不同干旱胁迫下,SOD、POD、CAT活性均随干旱胁迫程度的加剧呈现先升高后降低的趋势,而GR活性的变化则正好相反。上述结果表明,喀斯特环境下火棘种子能够通过种子萌发进程的调控和抗氧化保护酶活性的调节适应干旱环境胁迫。
In this study, Pyracantha fortuneana was invotved to study water- absorption regulation during seed germination process and the dynamic variations of several anti - oxidation enzymes activity including superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT）, glutathione reductase （GR）. The result showed the water absorption of seeds followed a ＂S - Curve＂ response to the extension of seed soaking time, with the maxi- mum of 18.14%, and seed germination experienced fast water absorbing phase at the initial 24h, stable water absorbing phase in the following 24 -220h, and saturated water absorption phase from 220h to 244h. Drought stress significantly affected seed germination course, and resulted in decreased germination rate, prolonged mean germination time, delayed initial germination as the strengthen of drought stress. The activities of four antioxidant enzymes changed polynomial, showing a trend of decrease after increase, and then rising up again at the second inflexion. Maximum of SOD and POD activity were observed at bud period, and imbibition period for CAT and GR activity（ though CAT activity was not significant between bud period and imbibition period）. The activities of SOD, POD, CAT followed a trend of decrease after increase as the strengthen of drought stress, while that of GR was just the opposite. Our results indicated that P. fortuneana seed could adapt to drought in Karst by the tion of seed germination course and the activities of antioxidant enzymes.
出处
《干旱区资源与环境》
CSSCI
CSCD
北大核心
2017年第9期135-139,共5页
Journal of Arid Land Resources and Environment
基金
贵州省体制改革项目(黔科合体Z字[2012]4005号)资助
关键词
火棘
种子萌发
干旱胁迫
生理指标
Pyracantha fortuneana
seed germination
drought stress
physiological indexes regula
